Data transfers between circuits often become unsynchronized due to many factors. For example, in voice-over-IP (VOIP) applications, the analog-to-digital codecs (such as a pulse-code-modulation PCM codec) may generate data at a rate different than the rate at which a signal processor can accept it. Buffer circuits typically provide a dynamic way to absorb and handle the ebb and flow of data being communicated between such circuits.
One typical buffering solution employs ring or circular buffers that have a fixed number of buffer elements. Respective read and write pointers or indices track the available buffer storage capacity. In some circumstances, the buffer may become full, causing an overwrite of the oldest data in the buffer. The indices identify this state by both pointing to the same buffer element location. When data is lost due to overwrites, noise in the system may result.
To minimize overwrites, large buffer configurations may be employed. The large buffers may be able to handle the various delays in operation between, for example, a PCM controller and a digital signal processor (DSP). Unfortunately, employing large buffers causes a corresponding increase in system latency and circuit space.